* [PATCH 01/11] blkcg: remove unnecessary request_list->blkg NULL test in blk_put_rl()
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 02/11] blkcg: use blkg_free() in blkcg_init_queue() failure path Tejun Heo
` (9 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
Since ec13b1d6f0a0 ("blkcg: always create the blkcg_gq for the root
blkcg"), a request_list always has its blkg associated. Drop
unnecessary rl->blkg NULL test from blk_put_rl().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
include/linux/blk-cgroup.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 1b62d76..9711fc2 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -394,8 +394,7 @@ static inline struct request_list *blk_get_rl(struct request_queue *q,
*/
static inline void blk_put_rl(struct request_list *rl)
{
- /* root_rl may not have blkg set */
- if (rl->blkg && rl->blkg->blkcg != &blkcg_root)
+ if (rl->blkg->blkcg != &blkcg_root)
blkg_put(rl->blkg);
}
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 02/11] blkcg: use blkg_free() in blkcg_init_queue() failure path
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
2015-07-11 18:00 ` [PATCH 01/11] blkcg: remove unnecessary request_list->blkg NULL test in blk_put_rl() Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 03/11] blkcg: remove unnecessary blkcg_root handling from css_alloc/free paths Tejun Heo
` (8 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
When blkcg_init_queue() fails midway after creating a new blkg, it
performs kfree() directly; however, this doesn't free the policy data
areas. Make it use blkg_free() instead. In turn, blkg_free() is
updated to handle root request_list special case.
While this fixes a possible memory leak, it's on an unlikely failure
path of an already cold path and the size leaked per occurrence is
miniscule too. I don't think it needs to be tagged for -stable.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index fbb0b65..64cc48f 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -70,7 +70,8 @@ static void blkg_free(struct blkcg_gq *blkg)
for (i = 0; i < BLKCG_MAX_POLS; i++)
kfree(blkg->pd[i]);
- blk_exit_rl(&blkg->rl);
+ if (blkg->blkcg != &blkcg_root)
+ blk_exit_rl(&blkg->rl);
kfree(blkg);
}
@@ -934,7 +935,7 @@ int blkcg_init_queue(struct request_queue *q)
radix_tree_preload_end();
if (IS_ERR(blkg)) {
- kfree(new_blkg);
+ blkg_free(new_blkg);
return PTR_ERR(blkg);
}
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 03/11] blkcg: remove unnecessary blkcg_root handling from css_alloc/free paths
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
2015-07-11 18:00 ` [PATCH 01/11] blkcg: remove unnecessary request_list->blkg NULL test in blk_put_rl() Tejun Heo
2015-07-11 18:00 ` [PATCH 02/11] blkcg: use blkg_free() in blkcg_init_queue() failure path Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 04/11] blkcg: restructure blkg_policy_data allocation in blkcg_activate_policy() Tejun Heo
` (7 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
blkcg_css_alloc() bypasses policy data allocation and blkcg_css_free()
bypasses policy data and blkcg freeing for blkcg_root. There's no
reason to to treat policy data any differently for blkcg_root. If the
root css gets allocated after policies are registered, policy
registration path will add policy data; otherwise, the alloc path
will. The free path isn't never invoked for root csses.
This patch removes the unnecessary special handling of blkcg_root from
css_alloc/free paths.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 64cc48f..2a493ce 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -819,18 +819,15 @@ static void blkcg_css_offline(struct cgroup_subsys_state *css)
static void blkcg_css_free(struct cgroup_subsys_state *css)
{
struct blkcg *blkcg = css_to_blkcg(css);
+ int i;
mutex_lock(&blkcg_pol_mutex);
list_del(&blkcg->all_blkcgs_node);
mutex_unlock(&blkcg_pol_mutex);
- if (blkcg != &blkcg_root) {
- int i;
-
- for (i = 0; i < BLKCG_MAX_POLS; i++)
- kfree(blkcg->pd[i]);
- kfree(blkcg);
- }
+ for (i = 0; i < BLKCG_MAX_POLS; i++)
+ kfree(blkcg->pd[i]);
+ kfree(blkcg);
}
static struct cgroup_subsys_state *
@@ -844,13 +841,12 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
if (!parent_css) {
blkcg = &blkcg_root;
- goto done;
- }
-
- blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
- if (!blkcg) {
- ret = ERR_PTR(-ENOMEM);
- goto free_blkcg;
+ } else {
+ blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL);
+ if (!blkcg) {
+ ret = ERR_PTR(-ENOMEM);
+ goto free_blkcg;
+ }
}
for (i = 0; i < BLKCG_MAX_POLS ; i++) {
@@ -877,7 +873,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
pol->cpd_init_fn(blkcg);
}
-done:
spin_lock_init(&blkcg->lock);
INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT);
INIT_HLIST_HEAD(&blkcg->blkg_list);
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 04/11] blkcg: restructure blkg_policy_data allocation in blkcg_activate_policy()
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (2 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 03/11] blkcg: remove unnecessary blkcg_root handling from css_alloc/free paths Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 05/11] blkcg: make blkcg_activate_policy() allow NULL ->pd_init_fn Tejun Heo
` (6 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
When a policy gets activated, it needs to allocate and install its
policy data on all existing blkg's (blkcg_gq's). Because blkg
iteration is protected by a spinlock, it currently counts the total
number of blkg's in the system, allocates the matching number of
policy data on a list and installs them during a single iteration.
This can be simplified by using speculative GFP_NOWAIT allocations
while iterating and falling back to a preallocated policy data on
failure. If the preallocated one has already been consumed, it
releases the lock, preallocate with GFP_KERNEL and then restarts the
iteration. This can be a bit more expensive than before but policy
activation is a very cold path and shouldn't matter.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
block/blk-cgroup.c | 55 ++++++++++++++++++----------------------------
include/linux/blk-cgroup.h | 3 ---
2 files changed, 21 insertions(+), 37 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 2a493ce..5dbbacd 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1043,65 +1043,52 @@ EXPORT_SYMBOL_GPL(blkio_cgrp_subsys);
int blkcg_activate_policy(struct request_queue *q,
const struct blkcg_policy *pol)
{
- LIST_HEAD(pds);
+ struct blkg_policy_data *pd_prealloc = NULL;
struct blkcg_gq *blkg;
- struct blkg_policy_data *pd, *nd;
- int cnt = 0, ret;
+ int ret;
if (blkcg_policy_enabled(q, pol))
return 0;
- /* count and allocate policy_data for all existing blkgs */
blk_queue_bypass_start(q);
- spin_lock_irq(q->queue_lock);
- list_for_each_entry(blkg, &q->blkg_list, q_node)
- cnt++;
- spin_unlock_irq(q->queue_lock);
-
- /* allocate per-blkg policy data for all existing blkgs */
- while (cnt--) {
- pd = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node);
- if (!pd) {
+pd_prealloc:
+ if (!pd_prealloc) {
+ pd_prealloc = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node);
+ if (!pd_prealloc) {
ret = -ENOMEM;
- goto out_free;
+ goto out_bypass_end;
}
- list_add_tail(&pd->alloc_node, &pds);
}
- /*
- * Install the allocated pds and cpds. With @q bypassing, no new blkg
- * should have been created while the queue lock was dropped.
- */
spin_lock_irq(q->queue_lock);
list_for_each_entry(blkg, &q->blkg_list, q_node) {
- if (WARN_ON(list_empty(&pds))) {
- /* umm... this shouldn't happen, just abort */
- ret = -ENOMEM;
- goto out_unlock;
- }
- pd = list_first_entry(&pds, struct blkg_policy_data, alloc_node);
- list_del_init(&pd->alloc_node);
+ struct blkg_policy_data *pd;
- /* grab blkcg lock too while installing @pd on @blkg */
- spin_lock(&blkg->blkcg->lock);
+ if (blkg->pd[pol->plid])
+ continue;
+
+ pd = kzalloc_node(pol->pd_size, GFP_NOWAIT, q->node);
+ if (!pd)
+ swap(pd, pd_prealloc);
+ if (!pd) {
+ spin_unlock_irq(q->queue_lock);
+ goto pd_prealloc;
+ }
blkg->pd[pol->plid] = pd;
pd->blkg = blkg;
pd->plid = pol->plid;
pol->pd_init_fn(blkg);
-
- spin_unlock(&blkg->blkcg->lock);
}
__set_bit(pol->plid, q->blkcg_pols);
ret = 0;
-out_unlock:
+
spin_unlock_irq(q->queue_lock);
-out_free:
+out_bypass_end:
blk_queue_bypass_end(q);
- list_for_each_entry_safe(pd, nd, &pds, alloc_node)
- kfree(pd);
+ kfree(pd_prealloc);
return ret;
}
EXPORT_SYMBOL_GPL(blkcg_activate_policy);
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 9711fc2..db82288 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -80,9 +80,6 @@ struct blkg_policy_data {
/* the blkg and policy id this per-policy data belongs to */
struct blkcg_gq *blkg;
int plid;
-
- /* used during policy activation */
- struct list_head alloc_node;
};
/*
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 05/11] blkcg: make blkcg_activate_policy() allow NULL ->pd_init_fn
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (3 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 04/11] blkcg: restructure blkg_policy_data allocation in blkcg_activate_policy() Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 06/11] blkcg: replace blkcg_policy->pd_size with ->pd_alloc/free_fn() methods Tejun Heo
` (5 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
blkg_create() allows NULL ->pd_init_fn() but blkcg_activate_policy()
doesn't. As both in-kernel policies implement ->pd_init_fn, it
currently doesn't break anything. Update blkcg_activate_policy() so
that its behavior is consistent with blkg_create().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 5dbbacd..b558705 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1079,7 +1079,8 @@ int blkcg_activate_policy(struct request_queue *q,
blkg->pd[pol->plid] = pd;
pd->blkg = blkg;
pd->plid = pol->plid;
- pol->pd_init_fn(blkg);
+ if (pol->pd_init_fn)
+ pol->pd_init_fn(blkg);
}
__set_bit(pol->plid, q->blkcg_pols);
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 06/11] blkcg: replace blkcg_policy->pd_size with ->pd_alloc/free_fn() methods
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (4 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 05/11] blkcg: make blkcg_activate_policy() allow NULL ->pd_init_fn Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 07/11] blk-throttle: remove asynchrnous percpu stats allocation mechanism Tejun Heo
` (4 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
A blkg (blkcg_gq) represents the relationship between a cgroup and
request_queue. Each active policy has a pd (blkg_policy_data) on each
blkg. The pd's were allocated by blkcg core and each policy could
request to allocate extra space at the end by setting
blkcg_policy->pd_size larger than the size of pd.
This is a bit unusual but was done this way mostly to simplify error
handling and all the existing use cases could be handled this way;
however, this is becoming too restrictive now that percpu memory can
be allocated without blocking.
This introduces two new mandatory blkcg_policy methods - pd_alloc_fn()
and pd_free_fn() - which are used to allocate and release pd for a
given policy. As pd allocation is now done from policy side, it can
simply allocate a larger area which embeds pd at the beginning. This
change makes ->pd_size pointless. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 21 +++++++++++----------
block/blk-throttle.c | 13 ++++++++++++-
block/cfq-iosched.c | 13 ++++++++++++-
include/linux/blk-cgroup.h | 18 +++++++++---------
4 files changed, 44 insertions(+), 21 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b558705..9d83623 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -68,7 +68,8 @@ static void blkg_free(struct blkcg_gq *blkg)
return;
for (i = 0; i < BLKCG_MAX_POLS; i++)
- kfree(blkg->pd[i]);
+ if (blkg->pd[i])
+ blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
if (blkg->blkcg != &blkcg_root)
blk_exit_rl(&blkg->rl);
@@ -114,7 +115,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
continue;
/* alloc per-policy data and attach it to blkg */
- pd = kzalloc_node(pol->pd_size, gfp_mask, q->node);
+ pd = pol->pd_alloc_fn(gfp_mask, q->node);
if (!pd)
goto err_free;
@@ -1053,7 +1054,7 @@ int blkcg_activate_policy(struct request_queue *q,
blk_queue_bypass_start(q);
pd_prealloc:
if (!pd_prealloc) {
- pd_prealloc = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node);
+ pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q->node);
if (!pd_prealloc) {
ret = -ENOMEM;
goto out_bypass_end;
@@ -1068,7 +1069,7 @@ int blkcg_activate_policy(struct request_queue *q,
if (blkg->pd[pol->plid])
continue;
- pd = kzalloc_node(pol->pd_size, GFP_NOWAIT, q->node);
+ pd = pol->pd_alloc_fn(GFP_NOWAIT, q->node);
if (!pd)
swap(pd, pd_prealloc);
if (!pd) {
@@ -1089,7 +1090,8 @@ int blkcg_activate_policy(struct request_queue *q,
spin_unlock_irq(q->queue_lock);
out_bypass_end:
blk_queue_bypass_end(q);
- kfree(pd_prealloc);
+ if (pd_prealloc)
+ pol->pd_free_fn(pd_prealloc);
return ret;
}
EXPORT_SYMBOL_GPL(blkcg_activate_policy);
@@ -1124,8 +1126,10 @@ void blkcg_deactivate_policy(struct request_queue *q,
if (pol->pd_exit_fn)
pol->pd_exit_fn(blkg);
- kfree(blkg->pd[pol->plid]);
- blkg->pd[pol->plid] = NULL;
+ if (blkg->pd[pol->plid]) {
+ pol->pd_free_fn(blkg->pd[pol->plid]);
+ blkg->pd[pol->plid] = NULL;
+ }
spin_unlock(&blkg->blkcg->lock);
}
@@ -1147,9 +1151,6 @@ int blkcg_policy_register(struct blkcg_policy *pol)
struct blkcg *blkcg;
int i, ret;
- if (WARN_ON(pol->pd_size < sizeof(struct blkg_policy_data)))
- return -EINVAL;
-
mutex_lock(&blkcg_pol_register_mutex);
mutex_lock(&blkcg_pol_mutex);
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index b231935..f1dd691 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -403,6 +403,11 @@ static void throtl_service_queue_exit(struct throtl_service_queue *sq)
del_timer_sync(&sq->pending_timer);
}
+static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
+{
+ return kzalloc_node(sizeof(struct throtl_grp), gfp, node);
+}
+
static void throtl_pd_init(struct blkcg_gq *blkg)
{
struct throtl_grp *tg = blkg_to_tg(blkg);
@@ -493,6 +498,11 @@ static void throtl_pd_exit(struct blkcg_gq *blkg)
throtl_service_queue_exit(&tg->service_queue);
}
+static void throtl_pd_free(struct blkg_policy_data *pd)
+{
+ kfree(pd);
+}
+
static void throtl_pd_reset_stats(struct blkcg_gq *blkg)
{
struct throtl_grp *tg = blkg_to_tg(blkg);
@@ -1468,12 +1478,13 @@ static void throtl_shutdown_wq(struct request_queue *q)
}
static struct blkcg_policy blkcg_policy_throtl = {
- .pd_size = sizeof(struct throtl_grp),
.cftypes = throtl_files,
+ .pd_alloc_fn = throtl_pd_alloc,
.pd_init_fn = throtl_pd_init,
.pd_online_fn = throtl_pd_online,
.pd_exit_fn = throtl_pd_exit,
+ .pd_free_fn = throtl_pd_free,
.pd_reset_stats_fn = throtl_pd_reset_stats,
};
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 9c9ec7c..69ce288 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1582,6 +1582,11 @@ static void cfq_cpd_init(const struct blkcg *blkcg)
}
}
+static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
+{
+ return kzalloc_node(sizeof(struct cfq_group), gfp, node);
+}
+
static void cfq_pd_init(struct blkcg_gq *blkg)
{
struct cfq_group *cfqg = blkg_to_cfqg(blkg);
@@ -1618,6 +1623,11 @@ static void cfq_pd_offline(struct blkcg_gq *blkg)
cfqg_stats_xfer_dead(cfqg);
}
+static void cfq_pd_free(struct blkg_policy_data *pd)
+{
+ return kfree(pd);
+}
+
/* offset delta from cfqg->stats to cfqg->dead_stats */
static const int dead_stats_off_delta = offsetof(struct cfq_group, dead_stats) -
offsetof(struct cfq_group, stats);
@@ -4633,13 +4643,14 @@ static struct elevator_type iosched_cfq = {
#ifdef CONFIG_CFQ_GROUP_IOSCHED
static struct blkcg_policy blkcg_policy_cfq = {
- .pd_size = sizeof(struct cfq_group),
.cpd_size = sizeof(struct cfq_group_data),
.cftypes = cfq_blkcg_files,
.cpd_init_fn = cfq_cpd_init,
+ .pd_alloc_fn = cfq_pd_alloc,
.pd_init_fn = cfq_pd_init,
.pd_offline_fn = cfq_pd_offline,
+ .pd_free_fn = cfq_pd_free,
.pd_reset_stats_fn = cfq_pd_reset_stats,
};
#endif
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index db82288..bd173ea 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -68,13 +68,11 @@ struct blkg_rwstat {
* request_queue (q). This is used by blkcg policies which need to track
* information per blkcg - q pair.
*
- * There can be multiple active blkcg policies and each has its private
- * data on each blkg, the size of which is determined by
- * blkcg_policy->pd_size. blkcg core allocates and frees such areas
- * together with blkg and invokes pd_init/exit_fn() methods.
- *
- * Such private data must embed struct blkg_policy_data (pd) at the
- * beginning and pd_size can't be smaller than pd.
+ * There can be multiple active blkcg policies and each blkg:policy pair is
+ * represented by a blkg_policy_data which is allocated and freed by each
+ * policy's pd_alloc/free_fn() methods. A policy can allocate private data
+ * area by allocating larger data structure which embeds blkg_policy_data
+ * at the beginning.
*/
struct blkg_policy_data {
/* the blkg and policy id this per-policy data belongs to */
@@ -126,16 +124,16 @@ struct blkcg_gq {
};
typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg);
+typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg);
+typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
struct blkcg_policy {
int plid;
- /* policy specific private data size */
- size_t pd_size;
/* policy specific per-blkcg data size */
size_t cpd_size;
/* cgroup files for the policy */
@@ -143,10 +141,12 @@ struct blkcg_policy {
/* operations */
blkcg_pol_init_cpd_fn *cpd_init_fn;
+ blkcg_pol_alloc_pd_fn *pd_alloc_fn;
blkcg_pol_init_pd_fn *pd_init_fn;
blkcg_pol_online_pd_fn *pd_online_fn;
blkcg_pol_offline_pd_fn *pd_offline_fn;
blkcg_pol_exit_pd_fn *pd_exit_fn;
+ blkcg_pol_free_pd_fn *pd_free_fn;
blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
};
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 07/11] blk-throttle: remove asynchrnous percpu stats allocation mechanism
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (5 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 06/11] blkcg: replace blkcg_policy->pd_size with ->pd_alloc/free_fn() methods Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 08/11] blk-throttle: clean up blkg_policy_data alloc/init/exit/free methods Tejun Heo
` (3 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
Because percpu allocator couldn't do non-blocking allocations,
blk-throttle was forced to implement an ad-hoc asynchronous allocation
mechanism for its percpu stats for cases where blkg's (blkcg_gq's) are
allocated from an IO path without sleepable context.
Now that percpu allocator can handle gfp_mask and blkg_policy_data
alloc / free are handled by policy methods, the ad-hoc asynchronous
allocation mechanism can be replaced with direct allocation from
tg_stats_alloc_fn(). Rit it out.
This ensures that an active throtl_grp always has valid non-NULL
->stats_cpu. Remove checks on it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-throttle.c | 112 ++++++++++++---------------------------------------
1 file changed, 25 insertions(+), 87 deletions(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index f1dd691..3c86976 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -144,9 +144,6 @@ struct throtl_grp {
/* Per cpu stats pointer */
struct tg_stats_cpu __percpu *stats_cpu;
-
- /* List of tgs waiting for per cpu stats memory to be allocated */
- struct list_head stats_alloc_node;
};
struct throtl_data
@@ -168,13 +165,6 @@ struct throtl_data
struct work_struct dispatch_work;
};
-/* list and work item to allocate percpu group stats */
-static DEFINE_SPINLOCK(tg_stats_alloc_lock);
-static LIST_HEAD(tg_stats_alloc_list);
-
-static void tg_stats_alloc_fn(struct work_struct *);
-static DECLARE_DELAYED_WORK(tg_stats_alloc_work, tg_stats_alloc_fn);
-
static void throtl_pending_timer_fn(unsigned long arg);
static inline struct throtl_grp *pd_to_tg(struct blkg_policy_data *pd)
@@ -256,53 +246,6 @@ static struct throtl_data *sq_to_td(struct throtl_service_queue *sq)
} \
} while (0)
-static void tg_stats_init(struct tg_stats_cpu *tg_stats)
-{
- blkg_rwstat_init(&tg_stats->service_bytes);
- blkg_rwstat_init(&tg_stats->serviced);
-}
-
-/*
- * Worker for allocating per cpu stat for tgs. This is scheduled on the
- * system_wq once there are some groups on the alloc_list waiting for
- * allocation.
- */
-static void tg_stats_alloc_fn(struct work_struct *work)
-{
- static struct tg_stats_cpu *stats_cpu; /* this fn is non-reentrant */
- struct delayed_work *dwork = to_delayed_work(work);
- bool empty = false;
-
-alloc_stats:
- if (!stats_cpu) {
- int cpu;
-
- stats_cpu = alloc_percpu(struct tg_stats_cpu);
- if (!stats_cpu) {
- /* allocation failed, try again after some time */
- schedule_delayed_work(dwork, msecs_to_jiffies(10));
- return;
- }
- for_each_possible_cpu(cpu)
- tg_stats_init(per_cpu_ptr(stats_cpu, cpu));
- }
-
- spin_lock_irq(&tg_stats_alloc_lock);
-
- if (!list_empty(&tg_stats_alloc_list)) {
- struct throtl_grp *tg = list_first_entry(&tg_stats_alloc_list,
- struct throtl_grp,
- stats_alloc_node);
- swap(tg->stats_cpu, stats_cpu);
- list_del_init(&tg->stats_alloc_node);
- }
-
- empty = list_empty(&tg_stats_alloc_list);
- spin_unlock_irq(&tg_stats_alloc_lock);
- if (!empty)
- goto alloc_stats;
-}
-
static void throtl_qnode_init(struct throtl_qnode *qn, struct throtl_grp *tg)
{
INIT_LIST_HEAD(&qn->node);
@@ -405,7 +348,27 @@ static void throtl_service_queue_exit(struct throtl_service_queue *sq)
static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
{
- return kzalloc_node(sizeof(struct throtl_grp), gfp, node);
+ struct throtl_grp *tg;
+ int cpu;
+
+ tg = kzalloc_node(sizeof(*tg), gfp, node);
+ if (!tg)
+ return NULL;
+
+ tg->stats_cpu = alloc_percpu_gfp(struct tg_stats_cpu, gfp);
+ if (!tg->stats_cpu) {
+ kfree(tg);
+ return NULL;
+ }
+
+ for_each_possible_cpu(cpu) {
+ struct tg_stats_cpu *stats_cpu = per_cpu_ptr(tg->stats_cpu, cpu);
+
+ blkg_rwstat_init(&stats_cpu->service_bytes);
+ blkg_rwstat_init(&stats_cpu->serviced);
+ }
+
+ return &tg->pd;
}
static void throtl_pd_init(struct blkcg_gq *blkg)
@@ -413,7 +376,6 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
struct throtl_grp *tg = blkg_to_tg(blkg);
struct throtl_data *td = blkg->q->td;
struct throtl_service_queue *parent_sq;
- unsigned long flags;
int rw;
/*
@@ -448,16 +410,6 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
tg->bps[WRITE] = -1;
tg->iops[READ] = -1;
tg->iops[WRITE] = -1;
-
- /*
- * Ugh... We need to perform per-cpu allocation for tg->stats_cpu
- * but percpu allocator can't be called from IO path. Queue tg on
- * tg_stats_alloc_list and allocate from work item.
- */
- spin_lock_irqsave(&tg_stats_alloc_lock, flags);
- list_add(&tg->stats_alloc_node, &tg_stats_alloc_list);
- schedule_delayed_work(&tg_stats_alloc_work, 0);
- spin_unlock_irqrestore(&tg_stats_alloc_lock, flags);
}
/*
@@ -487,20 +439,16 @@ static void throtl_pd_online(struct blkcg_gq *blkg)
static void throtl_pd_exit(struct blkcg_gq *blkg)
{
struct throtl_grp *tg = blkg_to_tg(blkg);
- unsigned long flags;
-
- spin_lock_irqsave(&tg_stats_alloc_lock, flags);
- list_del_init(&tg->stats_alloc_node);
- spin_unlock_irqrestore(&tg_stats_alloc_lock, flags);
-
- free_percpu(tg->stats_cpu);
throtl_service_queue_exit(&tg->service_queue);
}
static void throtl_pd_free(struct blkg_policy_data *pd)
{
- kfree(pd);
+ struct throtl_grp *tg = pd_to_tg(pd);
+
+ free_percpu(tg->stats_cpu);
+ kfree(tg);
}
static void throtl_pd_reset_stats(struct blkcg_gq *blkg)
@@ -508,9 +456,6 @@ static void throtl_pd_reset_stats(struct blkcg_gq *blkg)
struct throtl_grp *tg = blkg_to_tg(blkg);
int cpu;
- if (tg->stats_cpu == NULL)
- return;
-
for_each_possible_cpu(cpu) {
struct tg_stats_cpu *sc = per_cpu_ptr(tg->stats_cpu, cpu);
@@ -973,10 +918,6 @@ static void throtl_update_dispatch_stats(struct blkcg_gq *blkg, u64 bytes,
struct tg_stats_cpu *stats_cpu;
unsigned long flags;
- /* If per cpu stats are not allocated yet, don't do any accounting. */
- if (tg->stats_cpu == NULL)
- return;
-
/*
* Disabling interrupts to provide mutual exclusion between two
* writes on same cpu. It probably is not needed for 64bit. Not
@@ -1302,9 +1243,6 @@ static u64 tg_prfill_cpu_rwstat(struct seq_file *sf,
struct blkg_rwstat rwstat = { }, tmp;
int i, cpu;
- if (tg->stats_cpu == NULL)
- return 0;
-
for_each_possible_cpu(cpu) {
struct tg_stats_cpu *sc = per_cpu_ptr(tg->stats_cpu, cpu);
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 08/11] blk-throttle: clean up blkg_policy_data alloc/init/exit/free methods
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (6 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 07/11] blk-throttle: remove asynchrnous percpu stats allocation mechanism Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 09/11] blkcg: make blkcg_policy methods take a pointer to blkcg_policy_data Tejun Heo
` (2 subsequent siblings)
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
With the recent addition of alloc and free methods, things became
messier. This patch reorganizes them according to the followings.
* ->pd_alloc_fn()
Responsible for allocation and static initializations - the ones
which can be done independent of where the pd might be attached.
* ->pd_init_fn()
Initializations which require the knowledge of where the pd is
attached.
* ->pd_free_fn()
The counter part of pd_alloc_fn(). Static de-init and freeing.
This leaves ->pd_exit_fn() without any users. Removed.
While at it, collapse an one liner function throtl_pd_exit(), which
has only one user, into its user.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 11 ---------
block/blk-throttle.c | 57 ++++++++++++++++------------------------------
block/cfq-iosched.c | 15 ++++++++----
include/linux/blk-cgroup.h | 2 --
4 files changed, 31 insertions(+), 54 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 9d83623..e509bc8 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -402,15 +402,6 @@ static void blkg_destroy_all(struct request_queue *q)
void __blkg_release_rcu(struct rcu_head *rcu_head)
{
struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
- int i;
-
- /* tell policies that this one is being freed */
- for (i = 0; i < BLKCG_MAX_POLS; i++) {
- struct blkcg_policy *pol = blkcg_policy[i];
-
- if (blkg->pd[i] && pol->pd_exit_fn)
- pol->pd_exit_fn(blkg);
- }
/* release the blkcg and parent blkg refs this blkg has been holding */
css_put(&blkg->blkcg->css);
@@ -1123,8 +1114,6 @@ void blkcg_deactivate_policy(struct request_queue *q,
if (pol->pd_offline_fn)
pol->pd_offline_fn(blkg);
- if (pol->pd_exit_fn)
- pol->pd_exit_fn(blkg);
if (blkg->pd[pol->plid]) {
pol->pd_free_fn(blkg->pd[pol->plid]);
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 3c86976..c3a235b 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -330,26 +330,19 @@ static struct bio *throtl_pop_queued(struct list_head *queued,
}
/* init a service_queue, assumes the caller zeroed it */
-static void throtl_service_queue_init(struct throtl_service_queue *sq,
- struct throtl_service_queue *parent_sq)
+static void throtl_service_queue_init(struct throtl_service_queue *sq)
{
INIT_LIST_HEAD(&sq->queued[0]);
INIT_LIST_HEAD(&sq->queued[1]);
sq->pending_tree = RB_ROOT;
- sq->parent_sq = parent_sq;
setup_timer(&sq->pending_timer, throtl_pending_timer_fn,
(unsigned long)sq);
}
-static void throtl_service_queue_exit(struct throtl_service_queue *sq)
-{
- del_timer_sync(&sq->pending_timer);
-}
-
static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
{
struct throtl_grp *tg;
- int cpu;
+ int rw, cpu;
tg = kzalloc_node(sizeof(*tg), gfp, node);
if (!tg)
@@ -361,6 +354,19 @@ static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
return NULL;
}
+ throtl_service_queue_init(&tg->service_queue);
+
+ for (rw = READ; rw <= WRITE; rw++) {
+ throtl_qnode_init(&tg->qnode_on_self[rw], tg);
+ throtl_qnode_init(&tg->qnode_on_parent[rw], tg);
+ }
+
+ RB_CLEAR_NODE(&tg->rb_node);
+ tg->bps[READ] = -1;
+ tg->bps[WRITE] = -1;
+ tg->iops[READ] = -1;
+ tg->iops[WRITE] = -1;
+
for_each_possible_cpu(cpu) {
struct tg_stats_cpu *stats_cpu = per_cpu_ptr(tg->stats_cpu, cpu);
@@ -375,8 +381,7 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
{
struct throtl_grp *tg = blkg_to_tg(blkg);
struct throtl_data *td = blkg->q->td;
- struct throtl_service_queue *parent_sq;
- int rw;
+ struct throtl_service_queue *sq = &tg->service_queue;
/*
* If on the default hierarchy, we switch to properly hierarchical
@@ -391,25 +396,10 @@ static void throtl_pd_init(struct blkcg_gq *blkg)
* Limits of a group don't interact with limits of other groups
* regardless of the position of the group in the hierarchy.
*/
- parent_sq = &td->service_queue;
-
+ sq->parent_sq = &td->service_queue;
if (cgroup_on_dfl(blkg->blkcg->css.cgroup) && blkg->parent)
- parent_sq = &blkg_to_tg(blkg->parent)->service_queue;
-
- throtl_service_queue_init(&tg->service_queue, parent_sq);
-
- for (rw = READ; rw <= WRITE; rw++) {
- throtl_qnode_init(&tg->qnode_on_self[rw], tg);
- throtl_qnode_init(&tg->qnode_on_parent[rw], tg);
- }
-
- RB_CLEAR_NODE(&tg->rb_node);
+ sq->parent_sq = &blkg_to_tg(blkg->parent)->service_queue;
tg->td = td;
-
- tg->bps[READ] = -1;
- tg->bps[WRITE] = -1;
- tg->iops[READ] = -1;
- tg->iops[WRITE] = -1;
}
/*
@@ -436,17 +426,11 @@ static void throtl_pd_online(struct blkcg_gq *blkg)
tg_update_has_rules(blkg_to_tg(blkg));
}
-static void throtl_pd_exit(struct blkcg_gq *blkg)
-{
- struct throtl_grp *tg = blkg_to_tg(blkg);
-
- throtl_service_queue_exit(&tg->service_queue);
-}
-
static void throtl_pd_free(struct blkg_policy_data *pd)
{
struct throtl_grp *tg = pd_to_tg(pd);
+ del_timer_sync(&tg->service_queue.pending_timer);
free_percpu(tg->stats_cpu);
kfree(tg);
}
@@ -1421,7 +1405,6 @@ static struct blkcg_policy blkcg_policy_throtl = {
.pd_alloc_fn = throtl_pd_alloc,
.pd_init_fn = throtl_pd_init,
.pd_online_fn = throtl_pd_online,
- .pd_exit_fn = throtl_pd_exit,
.pd_free_fn = throtl_pd_free,
.pd_reset_stats_fn = throtl_pd_reset_stats,
};
@@ -1616,7 +1599,7 @@ int blk_throtl_init(struct request_queue *q)
return -ENOMEM;
INIT_WORK(&td->dispatch_work, blk_throtl_dispatch_work_fn);
- throtl_service_queue_init(&td->service_queue, NULL);
+ throtl_service_queue_init(&td->service_queue);
q->td = td;
td->queue = q;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 69ce288..4b795c7 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1584,7 +1584,17 @@ static void cfq_cpd_init(const struct blkcg *blkcg)
static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
{
- return kzalloc_node(sizeof(struct cfq_group), gfp, node);
+ struct cfq_group *cfqg;
+
+ cfqg = kzalloc_node(sizeof(*cfqg), gfp, node);
+ if (!cfqg)
+ return NULL;
+
+ cfq_init_cfqg_base(cfqg);
+ cfqg_stats_init(&cfqg->stats);
+ cfqg_stats_init(&cfqg->dead_stats);
+
+ return &cfqg->pd;
}
static void cfq_pd_init(struct blkcg_gq *blkg)
@@ -1592,11 +1602,8 @@ static void cfq_pd_init(struct blkcg_gq *blkg)
struct cfq_group *cfqg = blkg_to_cfqg(blkg);
struct cfq_group_data *cgd = blkcg_to_cfqgd(blkg->blkcg);
- cfq_init_cfqg_base(cfqg);
cfqg->weight = cgd->weight;
cfqg->leaf_weight = cgd->leaf_weight;
- cfqg_stats_init(&cfqg->stats);
- cfqg_stats_init(&cfqg->dead_stats);
}
static void cfq_pd_offline(struct blkcg_gq *blkg)
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index bd173ea..9879469 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -128,7 +128,6 @@ typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);
-typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg);
typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
@@ -145,7 +144,6 @@ struct blkcg_policy {
blkcg_pol_init_pd_fn *pd_init_fn;
blkcg_pol_online_pd_fn *pd_online_fn;
blkcg_pol_offline_pd_fn *pd_offline_fn;
- blkcg_pol_exit_pd_fn *pd_exit_fn;
blkcg_pol_free_pd_fn *pd_free_fn;
blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
};
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 09/11] blkcg: make blkcg_policy methods take a pointer to blkcg_policy_data
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (7 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 08/11] blk-throttle: clean up blkg_policy_data alloc/init/exit/free methods Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-11 18:00 ` [PATCH 10/11] blkcg: cosmetic updates about blkcg_policy_data Tejun Heo
2015-07-11 18:00 ` [PATCH 11/11] blkcg: replace blkcg_policy->cpd_size with ->cpd_alloc/free_fn() methods Tejun Heo
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
The newly added ->pd_alloc_fn() and ->pd_free_fn() deal with pd
(blkg_policy_data) while the older ones use blkg (blkcg_gq). As using
blkg doesn't make sense for ->pd_alloc_fn() and after allocation pd
can always be mapped to blkg and given that these are policy-specific
methods, it makes sense to converge on pd.
This patch makes all methods deal with pd instead of blkg. Most
conversions are trivial. In blk-cgroup.c, a couple method invocation
sites now test whether pd exists instead of policy state for
consistency. This shouldn't cause any behavioral differences.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
block/blk-cgroup.c | 18 ++++++++----------
block/blk-throttle.c | 13 +++++++------
block/cfq-iosched.c | 14 +++++++-------
include/linux/blk-cgroup.h | 8 ++++----
4 files changed, 26 insertions(+), 27 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e509bc8..d18cdb6 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -242,7 +242,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
struct blkcg_policy *pol = blkcg_policy[i];
if (blkg->pd[i] && pol->pd_init_fn)
- pol->pd_init_fn(blkg);
+ pol->pd_init_fn(blkg->pd[i]);
}
/* insert */
@@ -256,7 +256,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
struct blkcg_policy *pol = blkcg_policy[i];
if (blkg->pd[i] && pol->pd_online_fn)
- pol->pd_online_fn(blkg);
+ pol->pd_online_fn(blkg->pd[i]);
}
}
blkg->online = true;
@@ -347,7 +347,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
struct blkcg_policy *pol = blkcg_policy[i];
if (blkg->pd[i] && pol->pd_offline_fn)
- pol->pd_offline_fn(blkg);
+ pol->pd_offline_fn(blkg->pd[i]);
}
blkg->online = false;
@@ -468,9 +468,8 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
- if (blkcg_policy_enabled(blkg->q, pol) &&
- pol->pd_reset_stats_fn)
- pol->pd_reset_stats_fn(blkg);
+ if (blkg->pd[i] && pol->pd_reset_stats_fn)
+ pol->pd_reset_stats_fn(blkg->pd[i]);
}
}
@@ -1072,7 +1071,7 @@ int blkcg_activate_policy(struct request_queue *q,
pd->blkg = blkg;
pd->plid = pol->plid;
if (pol->pd_init_fn)
- pol->pd_init_fn(blkg);
+ pol->pd_init_fn(pd);
}
__set_bit(pol->plid, q->blkcg_pols);
@@ -1112,10 +1111,9 @@ void blkcg_deactivate_policy(struct request_queue *q,
/* grab blkcg lock too while removing @pd from @blkg */
spin_lock(&blkg->blkcg->lock);
- if (pol->pd_offline_fn)
- pol->pd_offline_fn(blkg);
-
if (blkg->pd[pol->plid]) {
+ if (pol->pd_offline_fn)
+ pol->pd_offline_fn(blkg->pd[pol->plid]);
pol->pd_free_fn(blkg->pd[pol->plid]);
blkg->pd[pol->plid] = NULL;
}
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index c3a235b..c2c7547 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -377,9 +377,10 @@ static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp, int node)
return &tg->pd;
}
-static void throtl_pd_init(struct blkcg_gq *blkg)
+static void throtl_pd_init(struct blkg_policy_data *pd)
{
- struct throtl_grp *tg = blkg_to_tg(blkg);
+ struct throtl_grp *tg = pd_to_tg(pd);
+ struct blkcg_gq *blkg = tg_to_blkg(tg);
struct throtl_data *td = blkg->q->td;
struct throtl_service_queue *sq = &tg->service_queue;
@@ -417,13 +418,13 @@ static void tg_update_has_rules(struct throtl_grp *tg)
(tg->bps[rw] != -1 || tg->iops[rw] != -1);
}
-static void throtl_pd_online(struct blkcg_gq *blkg)
+static void throtl_pd_online(struct blkg_policy_data *pd)
{
/*
* We don't want new groups to escape the limits of its ancestors.
* Update has_rules[] after a new group is brought online.
*/
- tg_update_has_rules(blkg_to_tg(blkg));
+ tg_update_has_rules(pd_to_tg(pd));
}
static void throtl_pd_free(struct blkg_policy_data *pd)
@@ -435,9 +436,9 @@ static void throtl_pd_free(struct blkg_policy_data *pd)
kfree(tg);
}
-static void throtl_pd_reset_stats(struct blkcg_gq *blkg)
+static void throtl_pd_reset_stats(struct blkg_policy_data *pd)
{
- struct throtl_grp *tg = blkg_to_tg(blkg);
+ struct throtl_grp *tg = pd_to_tg(pd);
int cpu;
for_each_possible_cpu(cpu) {
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4b795c7..95e6b0c 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1597,18 +1597,18 @@ static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
return &cfqg->pd;
}
-static void cfq_pd_init(struct blkcg_gq *blkg)
+static void cfq_pd_init(struct blkg_policy_data *pd)
{
- struct cfq_group *cfqg = blkg_to_cfqg(blkg);
- struct cfq_group_data *cgd = blkcg_to_cfqgd(blkg->blkcg);
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
+ struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg);
cfqg->weight = cgd->weight;
cfqg->leaf_weight = cgd->leaf_weight;
}
-static void cfq_pd_offline(struct blkcg_gq *blkg)
+static void cfq_pd_offline(struct blkg_policy_data *pd)
{
- struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
int i;
for (i = 0; i < IOPRIO_BE_NR; i++) {
@@ -1661,9 +1661,9 @@ static struct blkg_rwstat cfqg_rwstat_pd_recursive_sum(struct blkg_policy_data *
return a;
}
-static void cfq_pd_reset_stats(struct blkcg_gq *blkg)
+static void cfq_pd_reset_stats(struct blkg_policy_data *pd)
{
- struct cfq_group *cfqg = blkg_to_cfqg(blkg);
+ struct cfq_group *cfqg = pd_to_cfqg(pd);
cfqg_stats_reset(&cfqg->stats);
cfqg_stats_reset(&cfqg->dead_stats);
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 9879469..ddd4b8b 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -125,11 +125,11 @@ struct blkcg_gq {
typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg);
typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
-typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
-typedef void (blkcg_pol_online_pd_fn)(struct blkcg_gq *blkg);
-typedef void (blkcg_pol_offline_pd_fn)(struct blkcg_gq *blkg);
+typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
+typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
+typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
-typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
+typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
struct blkcg_policy {
int plid;
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 10/11] blkcg: cosmetic updates about blkcg_policy_data
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (8 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 09/11] blkcg: make blkcg_policy methods take a pointer to blkcg_policy_data Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
2015-07-30 22:57 ` [PATCH 10/11] blkcg: minor updates around blkcg_policy_data Tejun Heo
2015-07-11 18:00 ` [PATCH 11/11] blkcg: replace blkcg_policy->cpd_size with ->cpd_alloc/free_fn() methods Tejun Heo
10 siblings, 1 reply; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
* Rename blkcg->pd[] to blkcg->cpd[] so that cpd is consistently used
for blkcg_policy_data.
* Make blkcg_policy->cpd_init_fn() take blkcg_policy_data instead of
blkcg. This makes it consistent with blkg_policy_data methods and
to-be-added cpd alloc/free methods.
* blkcg_policy_data->blkcg and cpd_to_blkcg() added so that
cpd_init_fn() can determine the associated blkcg from
blkcg_policy_data.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
---
block/blk-cgroup.c | 22 +++++++++++-----------
block/cfq-iosched.c | 11 +++++------
include/linux/blk-cgroup.h | 14 ++++++++++----
3 files changed, 26 insertions(+), 21 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index d18cdb6..8173e06 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -817,7 +817,7 @@ static void blkcg_css_free(struct cgroup_subsys_state *css)
mutex_unlock(&blkcg_pol_mutex);
for (i = 0; i < BLKCG_MAX_POLS; i++)
- kfree(blkcg->pd[i]);
+ kfree(blkcg->cpd[i]);
kfree(blkcg);
}
@@ -853,15 +853,15 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
if (!pol || !pol->cpd_size)
continue;
- BUG_ON(blkcg->pd[i]);
+ BUG_ON(blkcg->cpd[i]);
cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
if (!cpd) {
ret = ERR_PTR(-ENOMEM);
goto free_pd_blkcg;
}
- blkcg->pd[i] = cpd;
+ blkcg->cpd[i] = cpd;
cpd->plid = i;
- pol->cpd_init_fn(blkcg);
+ pol->cpd_init_fn(cpd);
}
spin_lock_init(&blkcg->lock);
@@ -877,7 +877,7 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
free_pd_blkcg:
for (i--; i >= 0; i--)
- kfree(blkcg->pd[i]);
+ kfree(blkcg->cpd[i]);
free_blkcg:
kfree(blkcg);
mutex_unlock(&blkcg_pol_mutex);
@@ -1164,9 +1164,9 @@ int blkcg_policy_register(struct blkcg_policy *pol)
goto err_free_cpds;
}
- blkcg->pd[pol->plid] = cpd;
+ blkcg->cpd[pol->plid] = cpd;
cpd->plid = pol->plid;
- pol->cpd_init_fn(blkcg);
+ pol->cpd_init_fn(cpd);
}
}
@@ -1182,8 +1182,8 @@ int blkcg_policy_register(struct blkcg_policy *pol)
err_free_cpds:
if (pol->cpd_size) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
- kfree(blkcg->pd[pol->plid]);
- blkcg->pd[pol->plid] = NULL;
+ kfree(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
}
}
blkcg_policy[pol->plid] = NULL;
@@ -1218,8 +1218,8 @@ void blkcg_policy_unregister(struct blkcg_policy *pol)
if (pol->cpd_size) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
- kfree(blkcg->pd[pol->plid]);
- blkcg->pd[pol->plid] = NULL;
+ kfree(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
}
}
blkcg_policy[pol->plid] = NULL;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 95e6b0c..dd6ea9e 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -220,7 +220,7 @@ struct cfqg_stats {
/* Per-cgroup data */
struct cfq_group_data {
/* must be the first member */
- struct blkcg_policy_data pd;
+ struct blkcg_policy_data cpd;
unsigned int weight;
unsigned int leaf_weight;
@@ -612,7 +612,7 @@ static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd)
static struct cfq_group_data
*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
{
- return cpd ? container_of(cpd, struct cfq_group_data, pd) : NULL;
+ return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL;
}
static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg)
@@ -1568,12 +1568,11 @@ static void cfqg_stats_init(struct cfqg_stats *stats)
#endif
}
-static void cfq_cpd_init(const struct blkcg *blkcg)
+static void cfq_cpd_init(struct blkcg_policy_data *cpd)
{
- struct cfq_group_data *cgd =
- cpd_to_cfqgd(blkcg->pd[blkcg_policy_cfq.plid]);
+ struct cfq_group_data *cgd = cpd_to_cfqgd(cpd);
- if (blkcg == &blkcg_root) {
+ if (cpd_to_blkcg(cpd) == &blkcg_root) {
cgd->weight = 2 * CFQ_WEIGHT_DEFAULT;
cgd->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT;
} else {
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index ddd4b8b..7988d47 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -45,7 +45,7 @@ struct blkcg {
struct blkcg_gq *blkg_hint;
struct hlist_head blkg_list;
- struct blkcg_policy_data *pd[BLKCG_MAX_POLS];
+ struct blkcg_policy_data *cpd[BLKCG_MAX_POLS];
struct list_head all_blkcgs_node;
#ifdef CONFIG_CGROUP_WRITEBACK
@@ -88,7 +88,8 @@ struct blkg_policy_data {
* each policy handle per-blkcg data.
*/
struct blkcg_policy_data {
- /* the policy id this per-policy data belongs to */
+ /* the blkcg and policy id this per-policy data belongs to */
+ struct blkcg *blkcg;
int plid;
};
@@ -123,7 +124,7 @@ struct blkcg_gq {
struct rcu_head rcu_head;
};
-typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg);
+typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
@@ -243,7 +244,7 @@ static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
struct blkcg_policy *pol)
{
- return blkcg ? blkcg->pd[pol->plid] : NULL;
+ return blkcg ? blkcg->cpd[pol->plid] : NULL;
}
/**
@@ -257,6 +258,11 @@ static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
return pd ? pd->blkg : NULL;
}
+static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
+{
+ return cpd ? cpd->blkcg : NULL;
+}
+
/**
* blkg_path - format cgroup path of blkg
* @blkg: blkg of interest
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 10/11] blkcg: minor updates around blkcg_policy_data
2015-07-11 18:00 ` [PATCH 10/11] blkcg: cosmetic updates about blkcg_policy_data Tejun Heo
@ 2015-07-30 22:57 ` Tejun Heo
0 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-30 22:57 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna
>From 4b246538f4bdb143de8faec8b8ed4e4c18a862a8 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 30 Jul 2015 18:51:50 -0400
* Rename blkcg->pd[] to blkcg->cpd[] so that cpd is consistently used
for blkcg_policy_data.
* Make blkcg_policy->cpd_init_fn() take blkcg_policy_data instead of
blkcg. This makes it consistent with blkg_policy_data methods and
to-be-added cpd alloc/free methods.
* blkcg_policy_data->blkcg and cpd_to_blkcg() added so that
cpd_init_fn() can determine the associated blkcg from
blkcg_policy_data.
v2: blkcg_policy_data->blkcg initializations were missing. Added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
---
git branch updated accordingly.
Thanks.
block/blk-cgroup.c | 24 +++++++++++++-----------
block/cfq-iosched.c | 11 +++++------
include/linux/blk-cgroup.h | 14 ++++++++++----
3 files changed, 28 insertions(+), 21 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 8343450..247c42c 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -821,7 +821,7 @@ static void blkcg_css_free(struct cgroup_subsys_state *css)
mutex_unlock(&blkcg_pol_mutex);
for (i = 0; i < BLKCG_MAX_POLS; i++)
- kfree(blkcg->pd[i]);
+ kfree(blkcg->cpd[i]);
kfree(blkcg);
}
@@ -857,15 +857,16 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
if (!pol || !pol->cpd_size)
continue;
- BUG_ON(blkcg->pd[i]);
+ BUG_ON(blkcg->cpd[i]);
cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
if (!cpd) {
ret = ERR_PTR(-ENOMEM);
goto free_pd_blkcg;
}
- blkcg->pd[i] = cpd;
+ blkcg->cpd[i] = cpd;
+ cpd->blkcg = blkcg;
cpd->plid = i;
- pol->cpd_init_fn(blkcg);
+ pol->cpd_init_fn(cpd);
}
spin_lock_init(&blkcg->lock);
@@ -881,7 +882,7 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
free_pd_blkcg:
for (i--; i >= 0; i--)
- kfree(blkcg->pd[i]);
+ kfree(blkcg->cpd[i]);
free_blkcg:
kfree(blkcg);
mutex_unlock(&blkcg_pol_mutex);
@@ -1168,9 +1169,10 @@ int blkcg_policy_register(struct blkcg_policy *pol)
goto err_free_cpds;
}
- blkcg->pd[pol->plid] = cpd;
+ blkcg->cpd[pol->plid] = cpd;
+ cpd->blkcg = blkcg;
cpd->plid = pol->plid;
- pol->cpd_init_fn(blkcg);
+ pol->cpd_init_fn(cpd);
}
}
@@ -1186,8 +1188,8 @@ int blkcg_policy_register(struct blkcg_policy *pol)
err_free_cpds:
if (pol->cpd_size) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
- kfree(blkcg->pd[pol->plid]);
- blkcg->pd[pol->plid] = NULL;
+ kfree(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
}
}
blkcg_policy[pol->plid] = NULL;
@@ -1222,8 +1224,8 @@ void blkcg_policy_unregister(struct blkcg_policy *pol)
if (pol->cpd_size) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
- kfree(blkcg->pd[pol->plid]);
- blkcg->pd[pol->plid] = NULL;
+ kfree(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
}
}
blkcg_policy[pol->plid] = NULL;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 95e6b0c..dd6ea9e 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -220,7 +220,7 @@ struct cfqg_stats {
/* Per-cgroup data */
struct cfq_group_data {
/* must be the first member */
- struct blkcg_policy_data pd;
+ struct blkcg_policy_data cpd;
unsigned int weight;
unsigned int leaf_weight;
@@ -612,7 +612,7 @@ static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd)
static struct cfq_group_data
*cpd_to_cfqgd(struct blkcg_policy_data *cpd)
{
- return cpd ? container_of(cpd, struct cfq_group_data, pd) : NULL;
+ return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL;
}
static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg)
@@ -1568,12 +1568,11 @@ static void cfqg_stats_init(struct cfqg_stats *stats)
#endif
}
-static void cfq_cpd_init(const struct blkcg *blkcg)
+static void cfq_cpd_init(struct blkcg_policy_data *cpd)
{
- struct cfq_group_data *cgd =
- cpd_to_cfqgd(blkcg->pd[blkcg_policy_cfq.plid]);
+ struct cfq_group_data *cgd = cpd_to_cfqgd(cpd);
- if (blkcg == &blkcg_root) {
+ if (cpd_to_blkcg(cpd) == &blkcg_root) {
cgd->weight = 2 * CFQ_WEIGHT_DEFAULT;
cgd->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT;
} else {
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index ddd4b8b..7988d47 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -45,7 +45,7 @@ struct blkcg {
struct blkcg_gq *blkg_hint;
struct hlist_head blkg_list;
- struct blkcg_policy_data *pd[BLKCG_MAX_POLS];
+ struct blkcg_policy_data *cpd[BLKCG_MAX_POLS];
struct list_head all_blkcgs_node;
#ifdef CONFIG_CGROUP_WRITEBACK
@@ -88,7 +88,8 @@ struct blkg_policy_data {
* each policy handle per-blkcg data.
*/
struct blkcg_policy_data {
- /* the policy id this per-policy data belongs to */
+ /* the blkcg and policy id this per-policy data belongs to */
+ struct blkcg *blkcg;
int plid;
};
@@ -123,7 +124,7 @@ struct blkcg_gq {
struct rcu_head rcu_head;
};
-typedef void (blkcg_pol_init_cpd_fn)(const struct blkcg *blkcg);
+typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
@@ -243,7 +244,7 @@ static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
static inline struct blkcg_policy_data *blkcg_to_cpd(struct blkcg *blkcg,
struct blkcg_policy *pol)
{
- return blkcg ? blkcg->pd[pol->plid] : NULL;
+ return blkcg ? blkcg->cpd[pol->plid] : NULL;
}
/**
@@ -257,6 +258,11 @@ static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
return pd ? pd->blkg : NULL;
}
+static inline struct blkcg *cpd_to_blkcg(struct blkcg_policy_data *cpd)
+{
+ return cpd ? cpd->blkcg : NULL;
+}
+
/**
* blkg_path - format cgroup path of blkg
* @blkg: blkg of interest
--
2.4.3
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH 11/11] blkcg: replace blkcg_policy->cpd_size with ->cpd_alloc/free_fn() methods
2015-07-11 18:00 [PATCHSET v3 block/for-4.3] blkcg: blkcg policy methods and data handling cleanup Tejun Heo
` (9 preceding siblings ...)
2015-07-11 18:00 ` [PATCH 10/11] blkcg: cosmetic updates about blkcg_policy_data Tejun Heo
@ 2015-07-11 18:00 ` Tejun Heo
10 siblings, 0 replies; 13+ messages in thread
From: Tejun Heo @ 2015-07-11 18:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, kernel-team, vgoyal, avanzini.arianna, Tejun Heo
Each active policy has a cpd (blkcg_policy_data) on each blkcg. The
cpd's were allocated by blkcg core and each policy could request to
allocate extra space at the end by setting blkcg_policy->cpd_size
larger than the size of cpd.
This is a bit unusual but blkg (blkcg_gq) policy data used to be
handled this way too so it made sense to be consistent; however, blkg
policy data switched to alloc/free callbacks.
This patch makes similar changes to cpd handling.
blkcg_policy->cpd_alloc/free_fn() are added to replace ->cpd_size. As
cpd allocation is now done from policy side, it can simply allocate a
larger area which embeds cpd at the beginning.
As ->cpd_alloc_fn() may be able to perform all necessary
initializations, this patch makes ->cpd_init_fn() optional.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
---
block/blk-cgroup.c | 39 ++++++++++++++++++++++++---------------
block/cfq-iosched.c | 19 ++++++++++++++++++-
include/linux/blk-cgroup.h | 17 ++++++++++-------
3 files changed, 52 insertions(+), 23 deletions(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 8173e06..48d95ca 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -813,11 +813,15 @@ static void blkcg_css_free(struct cgroup_subsys_state *css)
int i;
mutex_lock(&blkcg_pol_mutex);
+
list_del(&blkcg->all_blkcgs_node);
- mutex_unlock(&blkcg_pol_mutex);
for (i = 0; i < BLKCG_MAX_POLS; i++)
- kfree(blkcg->cpd[i]);
+ if (blkcg->cpd[i])
+ blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
+
+ mutex_unlock(&blkcg_pol_mutex);
+
kfree(blkcg);
}
@@ -850,18 +854,18 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
* check if the policy requires any specific per-cgroup
* data: if it does, allocate and initialize it.
*/
- if (!pol || !pol->cpd_size)
+ if (!pol || !pol->cpd_alloc_fn)
continue;
- BUG_ON(blkcg->cpd[i]);
- cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
+ cpd = pol->cpd_alloc_fn(GFP_KERNEL);
if (!cpd) {
ret = ERR_PTR(-ENOMEM);
goto free_pd_blkcg;
}
blkcg->cpd[i] = cpd;
cpd->plid = i;
- pol->cpd_init_fn(cpd);
+ if (pol->cpd_init_fn)
+ pol->cpd_init_fn(cpd);
}
spin_lock_init(&blkcg->lock);
@@ -877,7 +881,8 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
free_pd_blkcg:
for (i--; i >= 0; i--)
- kfree(blkcg->cpd[i]);
+ if (blkcg->cpd[i])
+ blkcg_policy[i]->cpd_free_fn(blkcg->cpd[i]);
free_blkcg:
kfree(blkcg);
mutex_unlock(&blkcg_pol_mutex);
@@ -1154,11 +1159,11 @@ int blkcg_policy_register(struct blkcg_policy *pol)
blkcg_policy[pol->plid] = pol;
/* allocate and install cpd's */
- if (pol->cpd_size) {
+ if (pol->cpd_alloc_fn) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
struct blkcg_policy_data *cpd;
- cpd = kzalloc(pol->cpd_size, GFP_KERNEL);
+ cpd = pol->cpd_alloc_fn(GFP_KERNEL);
if (!cpd) {
mutex_unlock(&blkcg_pol_mutex);
goto err_free_cpds;
@@ -1180,10 +1185,12 @@ int blkcg_policy_register(struct blkcg_policy *pol)
return 0;
err_free_cpds:
- if (pol->cpd_size) {
+ if (pol->cpd_alloc_fn) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
- kfree(blkcg->cpd[pol->plid]);
- blkcg->cpd[pol->plid] = NULL;
+ if (blkcg->cpd[pol->plid]) {
+ pol->cpd_free_fn(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
+ }
}
}
blkcg_policy[pol->plid] = NULL;
@@ -1216,10 +1223,12 @@ void blkcg_policy_unregister(struct blkcg_policy *pol)
/* remove cpds and unregister */
mutex_lock(&blkcg_pol_mutex);
- if (pol->cpd_size) {
+ if (pol->cpd_alloc_fn) {
list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) {
- kfree(blkcg->cpd[pol->plid]);
- blkcg->cpd[pol->plid] = NULL;
+ if (blkcg->cpd[pol->plid]) {
+ pol->cpd_free_fn(blkcg->cpd[pol->plid]);
+ blkcg->cpd[pol->plid] = NULL;
+ }
}
}
blkcg_policy[pol->plid] = NULL;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index dd6ea9e..a4429b3 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1568,6 +1568,16 @@ static void cfqg_stats_init(struct cfqg_stats *stats)
#endif
}
+static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp)
+{
+ struct cfq_group_data *cgd;
+
+ cgd = kzalloc(sizeof(*cgd), GFP_KERNEL);
+ if (!cgd)
+ return NULL;
+ return &cgd->cpd;
+}
+
static void cfq_cpd_init(struct blkcg_policy_data *cpd)
{
struct cfq_group_data *cgd = cpd_to_cfqgd(cpd);
@@ -1581,6 +1591,11 @@ static void cfq_cpd_init(struct blkcg_policy_data *cpd)
}
}
+static void cfq_cpd_free(struct blkcg_policy_data *cpd)
+{
+ kfree(cpd_to_cfqgd(cpd));
+}
+
static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node)
{
struct cfq_group *cfqg;
@@ -4649,10 +4664,12 @@ static struct elevator_type iosched_cfq = {
#ifdef CONFIG_CFQ_GROUP_IOSCHED
static struct blkcg_policy blkcg_policy_cfq = {
- .cpd_size = sizeof(struct cfq_group_data),
.cftypes = cfq_blkcg_files,
+ .cpd_alloc_fn = cfq_cpd_alloc,
.cpd_init_fn = cfq_cpd_init,
+ .cpd_free_fn = cfq_cpd_free,
+
.pd_alloc_fn = cfq_pd_alloc,
.pd_init_fn = cfq_pd_init,
.pd_offline_fn = cfq_pd_offline,
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 7988d47..15f2382 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -81,11 +81,11 @@ struct blkg_policy_data {
};
/*
- * Policies that need to keep per-blkcg data which is independent
- * from any request_queue associated to it must specify its size
- * with the cpd_size field of the blkcg_policy structure and
- * embed a blkcg_policy_data in it. cpd_init() is invoked to let
- * each policy handle per-blkcg data.
+ * Policies that need to keep per-blkcg data which is independent from any
+ * request_queue associated to it should implement cpd_alloc/free_fn()
+ * methods. A policy can allocate private data area by allocating larger
+ * data structure which embeds blkcg_policy_data at the beginning.
+ * cpd_init() is invoked to let each policy handle per-blkcg data.
*/
struct blkcg_policy_data {
/* the blkcg and policy id this per-policy data belongs to */
@@ -124,7 +124,9 @@ struct blkcg_gq {
struct rcu_head rcu_head;
};
+typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp);
typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
+typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd);
typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp, int node);
typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
@@ -134,13 +136,14 @@ typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
struct blkcg_policy {
int plid;
- /* policy specific per-blkcg data size */
- size_t cpd_size;
/* cgroup files for the policy */
struct cftype *cftypes;
/* operations */
+ blkcg_pol_alloc_cpd_fn *cpd_alloc_fn;
blkcg_pol_init_cpd_fn *cpd_init_fn;
+ blkcg_pol_free_cpd_fn *cpd_free_fn;
+
blkcg_pol_alloc_pd_fn *pd_alloc_fn;
blkcg_pol_init_pd_fn *pd_init_fn;
blkcg_pol_online_pd_fn *pd_online_fn;
--
2.4.3
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